Notes:
Why would this model be useful? The risk arising from SPADs is understood as part of an overall safety model for the UK railway. It is not our purpose to access the overall risk.
Instead, this slides shows 4 possible uses. Where are SPADs most likely – we will like to identify areas, route or even signal likely to experience SPADs.
Operational processes, such as driver training, are carried out according to procedures and assessed by audit. We could use the results of these audits as observations in the bayesian network to sense changes in probabilities of SPADs – measuring Reasons currents in the safety space.
We could predict the effect of different interventions to reduce SPAD frequencies. Since the model is based on our understanding of courses of SPADs it could also be used in the investigation of SPAD incidents.